OBJECTIVES: To determine the preventive effect of green tea extract (GTE) supplements on metachronous colorectal adenoma and cancer in the Korean population.
MATERIALS AND METHODS: One hundred seventy-six subjects (88 per each group) who had undergone complete removal of colorectal adenomas by endoscopic polypectomy were enrolled. They were randomized into 2 groups: supplementation group (0.9 g GTE per day for 12 months) or control group without GTE supplementation. The 72-h recall method was used to collect data on food items consumed by participants at baseline and the 1-year follow-up during the past 48 h. Follow-up colonoscopy was conducted 12 months later in 143 patients (71 in control group and 72 in the GTE group).
RESULTS: Of the 143 patients completed in the study, the incidences of metachronous adenomas at the end-point colonoscopy were 42.3% (30 of 71) in control group and 23.6% (17 of 72) in GTE group (relative risk [RR], 0.56; 95% confidence interval [CI], 0.34-0.92). The number of relapsed adenoma was also decreased in the GTE group than in the control group (0.7 ± 1.1 vs. 0.3 ± 0.6, p = 0.010). However, there were no significant differences between the 2 groups in terms of body mass index, dietary intakes, serum lipid profiles, fasting serum glucose, and serum C-reactive protein levels (all p > 0.05).
CONCLUSION: This study of GTE supplement suggests a favorable outcome for the chemoprevention of metachronous colorectal adenomas in Korean patients (ClinicalTrials.gov number, NCT02321969).
Shin CM, et al. Green tea extracts for the prevention of metachronous colorectal polyps among patients who underwent endoscopic removal of colorectal adenomas: A randomized clinical trial. Clin Nutr. 2018 Apr;37(2):452-458. doi: 10.1016/j.clnu.2017.01.014. Epub 2017 Jan 29.